To develop a container suitable for carrying vinegared rice balls refrigerated or preserved at a normal temperature and convenient upon usage, and to develop a container shape and a packaging method which solve the problems which occur upon microwave heating.

A dividing wall 1a has a height that is 50 to 60% of the height of a vinegared rice ball 2, thereby suppressing shape collapse that is caused by shock during carriage. The convenience upon usage is improved by providing a notch in the dividing wall. Regarding dew adhesion and drying of the vinegared rice ball upon microwave heating, several bar-like protrusions 1b are provided on the bottom of the container, and a paper sheet 3 is placed on the vinegared rice ball. Thus, deterioration in the commercial value is suppressed.